1. Field of the Invention
This invention relates generally to encryption devices and more specifically to a device for encrypting voice signals and data including facsimile transmission data between any telephone system and individual cellular telephones. The telephone system may be a public switched telephone.
2. Background
A communications security device that is economical, commercially available, easy to use and which maintains the privacy and security of both voice and data is critical to the maintenance of U.S. competitiveness in both local and global market-places. The information age has brought along with it the concept that information in the form of ideas, strategies, bids, and product specifications is a very valuable asset and worth considerable sums of money. The idea of industrial espionage, the attacking and exploiting of the information resources of others, is not new. In fact, in April, 1992 Robert Gates, Director of Central Intelligence, testified before Congress that both friend and foe alike were conducting industrial espionage in the United States. With the advent of the digital computer and its ability to store and process collected information, the need to maintain the security of these valuable assets has become all the more important . . . and difficult.
The most common transmission means for information between human beings in the information age is still analog voice through common telephony means. The common telephony means now predominently used by the corporate executive is analog cellular telephones communicating over public switched telephone equipment. For purposes of simplicity, public switched telephones shall be used to refer to both analog and digital telephone systems. The need for secure point to point communications with a caller identification and compartmentalization scheme is apparent considering the interests of corporate privacy and security.
The present invention, a Voice and Data Encryption Device (V/DED) is a security module designed specifically for use with analog cellular and public switched telephone systems as well as with other equipment such as computers and facsimile machines. The V/DED provides telephone users with the capability to enhance the privacy and security of their voice and data transmission in an effective fashion and at a reasonable price. A software implemented security key provides protection from compromise for the information life of most commercial information. The V/DED operates in three different modes: nonsecure, plain text mode, privacy (i.e. universal table) mode, and keyed privacy (i.e. private tables used within a given organization) modes. The information security model developed around the V/DED utilizes a standard encryption technique such as the Data Encryption Standard described in Federal Information Processing Standard Pub. No. 46, 1/77 issued by the National Institute of Science and Technology, Department of Commerce, which is incorporated herein by reference in order to reach the broadest base of information systems. Thus government and commercial firms can utilize dual role (encrypted and non-encrypted) secure cellular, public switched telephone, and data communication capability in a cost effective manner.